why read books from different disciplines?

why read a range of topics ? - to enhance your worldview, gain understanding of the world, refer Meditations by Marcus Aurelius, Range by David Epstein

A central theme to Meditations is the importance of analyzing one's judgment of self and others and developing a cosmic perspective:

"You have the power to strip away many superfluous troubles located wholly in your judgment, and to possess a large room for yourself embracing in thought the whole cosmos, to consider everlasting time, to think of the rapid change in the parts of each thing, of how short it is from birth until dissolution, and how the void before birth and that after dissolution are equally infinite."

absorb knowledge from anyhwere you can get - but understand the context in which it could be applied in your situation - do not copy paste - something that worked for another person might not necessarily work you

how to read more books ? - refer mark manson's vid - youtube search for how to be a better reader